With such a small and convenient caliper, it is easy to accurately test yourself in the privacy of your own home (see instructions). The caliper also has a unique feature that of a sliding marker that will remain after testing each site so that you can check your measurement before resetting it. This product includes an instruction booklet with all the information you need for body fat measurement, including body fat measurement charts and a chart for tracking results, making it a great do-it-yourself kit.